The investigation process must begin somewhere, and most often, investigators start their investigation with interviews of "witnesses" claiming to have "first-hand information" about the incident. The well-educated investigator will not start his or her interview, with the "sidewalk commanders;" rather with those who were truly "first" on-scene: fire personnel.
Construct a list of five to ten logical and methodical questions that you would ask first arriving fire crews following a single-family residential fire. Give this matter some thought as you should ask questions in logical order.